"Please report the incident to Pantheon Terminal developers" after launching another terminal from CLI

### What Happened?

When launching a different terminal emulator (Alacritty, XTerm, ...) from inside Pantheon Terminal, this message appears:
> You should not have seen this, please report the incident to the Pantheon Terminal developers.

The launched terminal also causes a "Process completed" notification for every command executed.

### Steps to Reproduce

1. Install either Alacritty or XTerm
2. Open Terminal
3. Run `alacritty` or `xterm`, run some commands
4. See notifications

### Expected Behavior

No notifications.

### OS Version

8.x (Circe)

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

- Using `fish` as shell